Combined Air Waveguide Antenna and Housing

The present disclosure relates to a waveguide antenna and housing, and more particularly to a combined multi-piece air waveguide antenna and housing.

Waveguide antennas are widely used in various applications including automotive, telecommunications, radar systems, satellite communication, and wireless networks to transmit and receive electromagnetic signals with minimal loss and distortion. The waveguide antenna radiates an electromagnetic wave, (e.g., of a millimeter band) in a desired direction and receives a reflected wave from objects in front of the radar to detect possible objects. A radar system may comprise an air waveguide antenna and a printed circuit board (PCB). Conventional waveguide antennas typically consist of metallic waveguides enclosed within a protective housing. The installation of waveguide antennas can be complex and time-consuming, requiring precise alignment and calibration. While known waveguide antennas have proven acceptable for their intended purposes, a continuous need for improvement in the relevant art remains.

The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

One aspect of the disclosure provides a waveguide antenna assembly. The waveguide antenna assembly includes a lower housing, an upper housing, and a printed circuit board (PCB). The lower housing is formed, at least in part, from a conductive material. The upper housing is coupled to the lower housing and is formed, at least in part, from a conductive material. The upper housing and the lower housing define a slot. The printed circuit board (PCB) is disposed within the slot and includes a first side and a second side. The first side faces the lower housing and includes a first plurality of components arranged in a first circuit. The second side faces the upper housing and includes a second plurality of components arranged in a second circuit.

Another aspect of the disclosure provides a printed circuit board (PCB) assembly. The PCB assembly includes a PCB, a first fin, and a microstrip feed line. The PCB includes a first side and a second side. The first side includes a first plurality of components arranged in a first circuit. The second side opposes the first side and includes a second plurality of components arranged in a second circuit. The first fin is arranged in the first circuit and defines a first long curve and a first short curve. The first fin is disposed on the first side of the PCB. The microstrip feed line is connected to the first fin.

Another aspect of the disclosure provides a printed circuit board (PCB) assembly. The PCB assembly includes a PCB, a first fin, a parasitic fin, and a microstrip feed line. The PCB includes a first side and a second side. The first side includes a first plurality of components arranged in a first circuit. The first fin is arranged in the first circuit and is disposed on the first side of the PCB. The parasitic fin arranged is in the first circuit and is disposed on the first side of the PCB. The microstrip feed line is connected to the first fin.

Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

In the drawings, reference numbers may be reused to identify similar and/or identical elements.

Example configurations will now be described more fully with reference to the accompanying drawings. Example configurations are provided so that this disclosure will be thorough, and will fully convey the scope of the disclosure to those of ordinary skill in the art. Specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of configurations of the present disclosure. It will be apparent to those of ordinary skill in the art that specific details need not be employed, that example configurations may be embodied in many different forms, and that the specific details and the example configurations should not be construed to limit the scope of the disclosure.

Referring to, a waveguide antenna assemblyhaving a printed circuit board (PCB)-waveguide transition is illustrated. In operation, the waveguide antenna assemblymay be coupled to, or otherwise disposed on, a vehicle(e.g., a car, a truck, a sport utility vehicle, etc.) to guide waves (e.g., RF waves) transmitted and/or received by the waveguide antenna assembly. The waveguide antenna assemblymay include an upper housing, a lower housing, and a PCB assembly. The upper housingmay be coupled to the lower housing. The upper housingand lower housingmay define a slot. The PCB assemblymay be disposed within the slot.

The PCB assemblymay include a PCBincluding a first sideand a second side. The second sidemay be opposite the first side. The first sidemay face the lower housing. The second sidemay face the upper housing. The first sidemay include a first plurality of components(e.g., a monolithic microwave integrated circuit, or MMIC) arranged in a first circuit. The second sidemay include a second plurality of componentsarranged in a second circuit. In some configurations, the PCBmay be a two-layer PCB.

Referring to, the upper housingmay include one or more waveguide channelsand one or more radiator openingsin fluid communication with the one or more waveguide channels. The one or more radiator openingsmay be disposed on an outer surfaceof the upper housing. The one or more waveguide channelsmay be disposed on an inner surfaceof the upper housing. The waveguide channelsmay guide waves (e.g., RF waves propagated by the PCB assemblyor a component) out of the radiator openings. In some configurations, a dielectric material(e.g., a low loss dielectric material) is disposed within at least one of the radiator openings.

The upper housingmay be formed from an electrically-conductive and/or thermally-conductive material. For example, in some implementations, the upper housingis formed at least partially out of metal (e.g., steel, aluminum, etc.) and/or an electrically-conductive and/or thermally-conductive plastic (e.g., metalized plastic). In some configurations, the upper housingpulls heat energy away from the PCB assemblyto cool the PCB assemblyand/or the components. For example, the upper housingmay act as a heat-sink for the PCB assemblyand/or the componentsto facilitate the transfer of heat from the PCB assemblyto the upper housing.

In some configurations, the upper housingshields electromagnetic interference (EMI)/radio frequency interference (RFI) to prevent the EMI/RFI from disrupting operation of the PCB assemblyand/or the components. For example, the upper housingmay shield the PCB assemblyand/or the componentsfrom EMI/RFI. In some configurations, the upper housingdefines an opening() in communication (e.g., fluid communication) with the slot. The PCB assemblymay be disposed within the opening. In some configurations, the slotand the openingare defined at least in part by an upper surface() of the upper housing. The upper surfacemay be planar.

Referring to, the lower housingmay include one or more waveguide channels. The waveguide channelsmay be in fluid communication with the waveguide channelsof the upper housing. The one or more waveguide channelsmay be disposed on an inner surfaceof the lower housing. The waveguide channelsmay guide waves (e.g., RF waves propagated by the PCB assemblyor a component) to the waveguide channelsof the upper housingand out of the radiator openings.

The lower housingmay be formed from an electrically-conductive and/or thermally-conductive material. For example, in some implementations, the lower housingis formed at least partially out of metal (e.g., steel, aluminum, etc.) and/or an electrically-conductive and/or thermally-conductive plastic (e.g., metalized plastic). In some configurations, the lower housingpulls heat energy away from the PCB assemblyto cool the PCB assemblyand/or the components. For example, the lower housingmay act as a heat-sink for the PCB assemblyand/or the componentsto facilitate the transfer of heat from the PCB assemblyto the lower housing. In some configurations, the lower housingshields electromagnetic interference (EMI)/radio frequency interference (RFI) to prevent the EMI/RFI from disrupting operation of the PCB assemblyand the components. For example, the lower housingmay shield the PCB assemblyand/or the componentsfrom EMI/RFI. In some configurations, the lower housingreduces EMI/RFI emissions from radar. In some configurations, the lower housingat least partially defines the opening.

In some implementations, one or both of the upper housingor the lower housingmay function as a radome. In this regard, the waveguide antenna assemblymay not include a separate radome.

In some implementations, the upper housingand lower housingmay be symmetric or nearly symmetric, which decreases the internal thermal stress on the upper housingand/or lower housingand reduces warpage.

Referring to, the lower housingand the first sideof the PCBmay define a first waveguide channelfor a PCB-waveguide transition. The first waveguide channelmay be in communication (e.g., fluid communication) with the slotand/or the opening. The first waveguide channelmay provide EMI shielding for the PCB assemblyand/or components.

The waveguide antenna assemblymay further include a first pedestaldisposed within the first waveguide channel. The first pedestalmay engage the lower housingand at least one componentof the first plurality of components. The first pedestalmay connect the componentto the lower housingto provide heat-sinking and facilitate the transfer of heat from the PCB assemblyto the lower housing. While the waveguide antenna assemblyis generally shown and described herein as including one first pedestalengaging the lower housingand at least one componentof the first plurality of components, it will be appreciated that the waveguide antenna assemblymay include a plurality of pedestalseach engaging the lower housingand at least one componentof the first plurality of componentswithin the scope of the present disclosure. A thermal interface materialmay be disposed between the first pedestal(s)and the component(s)to further increase the heat-sinking capability of the lower housing.

The second sideof the PCBand the upper housingmay define a cavity. The cavitymay be in communication (e.g., fluid communication) with the slotand/or the opening.

The waveguide antenna assemblymay further include a second pedestaldisposed within the cavity. The second pedestalmay engage the upper housingand at least one componentof the second plurality of components. The second pedestalmay connect the componentto the upper housingto provide heat-sinking and facilitate the transfer of heat from the PCB assemblyto the upper housing. While the waveguide antenna assemblyis generally shown and described herein as including one second pedestalengaging the upper housingand at least one componentof the second plurality of components, it will be appreciated that the waveguide antenna assemblymay include a plurality of pedestalseach engaging the upper housingand at least one componentof the second plurality of componentswithin the scope of the present disclosure.

A thermal interface materialmay be disposed between the second pedestal(s)and the component(s)to further increase the heat-sinking capability of the upper housing. The increased heat-sinking capability of the upper housingand the lower housingmay increase the radio frequency performance of the waveguide antenna assemblyby allowing for more transmit dwell before reaching the thermal limit of the waveguide antenna assemblyor PCB assembly.

Referring to, the waveguide antenna assemblymay include a connector(e.g., an electrical connector). The connectormay be coupled to the lower housingand/or the upper housing. The connectormay be in communication (e.g., electrical communication) with the PCB assembly. The connectormay connect the PCB assemblyto an external electrical system (e.g., an electrical system of the vehicle). The connectormay provide power to the PCB assembly. In some configurations, the connectoris sealed from the external environment.

Referring to, in addition to the PCB, the PCB assemblymay include one or more Vivaldi antenna fins-,-, a microstrip feed line, and one or more via fences. A first Vivaldi fin-may be disposed on the first sideof the PCBand a second Vivaldi fin-may be disposed on the second sideof the PCB. The one or more via fencesmay connect the PCB assemblyand/or the PCBto the upper housingor the lower housing. Specifically, the one or more via fencesmay electrically connect the one or more Vivaldi fins-,-to the upper housingor the lower housing. The microstrip feed linemay be disposed on the first sideof the PCBand connected (e.g., electrically connected) to the first Vivaldi fin-. Additionally, the one or more via fencesmay connect (e.g., electrically connect) the upper housingto the lower housing.

The first Vivaldi fin-may make at least partial contact with the inner surfaceof the lower housing, and the second Vivaldi fin-may make at least partial contact with the inner surfaceof the upper housing.

The first Vivaldi fin-may include a first side-defined by a long curve-and a second side-defined by a short curve-. The first side-may be adjacent to the second side-. The long curve-may be defined by a first exponential function y=a·b, where “a” is a first constant, “b” is a second constant, and “x” is a variable value. The short curve-may be defined by a second exponential function y=c·d, where “c” is a third constant, “d” is a fourth constant, and “x” is a variable value. The first exponential function and the second exponential function may be different exponential functions. For example, if “a” is equal to “c,” then “b” is not equal to “d,” or vice versa. The first Vivaldi fin-may match the second Vivaldi fin-. Specifically, the second Vivaldi fin-may include a second long curve-and a second short curve-. The first long curve-may match the second long curve-. For example, the first long curve-may include the same size and/or shape as the second long curve-. The first short curve-may match the second short curve-. For example, the first short curve-may include the same size and/or shape as the second short curve-. The long curves-,-and the short curves-,-may at least partially define the shape of the Vivaldi fins-,-. The shape of the Vivaldi fins-,-may determine the resonant frequency, impedance matching, and bandwidth of the waveguide antenna assembly.

The Vivaldi fins-,-may act as a field (e.g., electromagnetic field) converter. For example, the Vivaldi fins-,-may rotate fields (e.g., electric fields) carried by the microstrip feed line(e.g., Transverse Electromagnetic (TEM) mode) and then gradually flare out the electric fields along the Vivaldi fins-,-to match the fundamental mode (e.g., Transverse Electric(TE) mode) of the waveguide antenna assembly.shows the change of the electric fields at four plane cuts w, x, y, z during the mode conversion process using the PCB assembly. The simulation results ofshow matching at both the microstrip feed lineand waveguide ports (denoted as “w” in), indicating a successful mode conversion process.

In some configurations, the PCB assemblyincludes a matching sectiondisposed between and connecting the Vivaldi fin-,-and the microstrip feed line. The matching sectionmay be wider or narrower than the microstrip feed linedepending on material properties, shape of the Vivaldi fins-,-, and/or size of the waveguide antenna assembly.

Referring to, in a first exemplary design of the PCB assembly, the PCB assemblymay include a thin substrate PCB. In some configurations, the thin substrate PCBis approximatelymicrometers thick. The Vivaldi fins-,-may include a matching arch. The matching archmay enhance the bandwidth matching of the waveguide antenna assembly.

Referring to, a waveguide antenna assemblymay include the upper housing, the lower housing, and a PCB assembly. In view of the substantial similarity in structure and function of the components associated with the waveguide antenna assemblywith respect to the waveguide antenna assembly, like reference numerals are used hereinafter and in the drawings to identify like components while like reference numerals containing letter extensions (e.g., “a”) are used to identify those components that have been modified. The PCB assemblymay be a thick substrate PCB assembly. The thick substrate may be thicker than the thin substrate of the PCB assembly. A thick substrate may be used due to ease or cost to manufacture.

The thick substrate PCB assemblymay include an additional layer(e.g., a PCB having a thickness greater than the thickness of the PCB) and a parasitic fin. In some configurations, the additional layer is approximatelymicrometers thick. In some configurations, the additional layeris composed of multiple layers of dielectric materials with various layer thickness and material properties (e.g., dielectric constant (Dk) and loss tangent (tanD)). The parasitic finmay be disposed on a second sideof the PCB assembly. The parasitic finmay be disposed near the second Vivaldi fin-. In some configurations, there is a gap of approximately.millimeters between the parasitic finand the second Vivaldi fin-. In this configuration, the Vivaldi fins-,-may not include the matching arch. In this configuration, the long curveand the short curveof the second Vivaldi fin-may be tuned (e.g., shaped) for impedance matching. The additional layermay affect (e.g., attract) the electric fields. The parasitic finmay counteract the effect of the additional layeron the electric fields.shows the change of the electric fields at six plane cuts a, b, c, d, e, f during the mode conversion process using the PCB assembly.shows simulation results of the performance of the thick PCB assemblyincluding the parasitic fin.

Referring to, a waveguide antenna assemblymay include the upper housing, the lower housing, and one or more PCB assemblies (e.g., PCB assemblyand/or PCB assembly). In view of the substantial similarity in structure and function of the components associated with the waveguide antenna assemblywith respect to the waveguide antenna assembly, like reference numerals are used hereinafter and in the drawings to identify like components while like reference numerals containing letter extensions (e.g., “b”) are used to identify those components that have been modified. In some configurations, the waveguide antenna assemblymay include a plurality of PCB assemblies (e.g., PCB assemblyand/or PCB assembly) arranged in an array (e.g., straight or staggered). In this configuration, the upper housingor the lower housingincludes multiple openingsand each PCB assembly is disposed within an opening. Energy may leak from one openingto another openingreducing the performance of the waveguide antenna assembly. An isolation slotmay be placed on one or both of the first sideand second sideof each PCB assembly. The isolation slotsmay prevent energy from leaking from one openingto another opening, thereby improving performance of the waveguide antenna assembly.show the simulated performance of the waveguide antenna assemblyusing the isolation slots.

The following Clauses provide an exemplary configuration for a waveguide antenna and housing, as described above.

Clause 1: A waveguide antenna assembly comprising: a lower housing formed at least in part from a conductive material; an upper housing coupled to the lower housing and formed at least in part from a conductive material, the upper housing and the lower housing defining a slot; and a printed circuit board (PCB) disposed within the slot and including a first side and a second side, the first side facing the lower housing and including a first plurality of components arranged in a first circuit, the second side facing the upper housing and including a second plurality of components arranged in a second circuit.

Clause 2: The waveguide antenna assembly of clause 1, wherein the upper housing and the lower housing are configured to provide heat-sinking to the PCB.

Clause 3: The waveguide antenna assembly of any of clauses 1 through 2, wherein the upper housing and the lower housing are configured to provide shielding to the PCB.

Clause 4: The waveguide antenna assembly of any of clauses 1 through 3, wherein at least one of the lower housing or the upper housing defines an opening in communication with the slot, and wherein the PCB is disposed within the opening.

Clause 5: The waveguide antenna assembly of clause 4, wherein the slot and the opening are defined at least in part by an upper surface of the upper housing, and wherein the upper surface is planar.

Clause 6: The waveguide antenna assembly of any of clauses 1 through 5, wherein the waveguide antenna assembly does not include a radome.

Clause 7: The waveguide antenna assembly of any of clauses 1 through 6, wherein the first side and the lower housing define a first waveguide channel in communication with the slot.

Clause 8: The waveguide antenna assembly of clause 7, further comprising a first pedestal disposed within the first waveguide channel and engaging the lower housing and at least one component of the first plurality of components.

Clause 9: The waveguide antenna assembly of clause 8, further comprising a thermal interface material disposed between the first pedestal and the at least one component of the first plurality of components.

Clause 10: The waveguide antenna assembly of any of clauses 1 through 9, wherein the second side and the upper housing define a cavity in communication with the slot.

Clause 11: The waveguide antenna assembly of clause 10, further comprising a second pedestal disposed within the cavity and engaging the upper housing and at least one component of the second plurality of components.

Clause 12: The waveguide antenna assembly of clause 11, further comprising a first pedestal disposed within a first waveguide channel and engaging the lower housing and at least one component of the first plurality of components.

Clause 13: The waveguide antenna assembly of clause 11, further comprising a thermal interface material disposed between the second pedestal and the at least one component of the second plurality of components.

Clause 14: The waveguide antenna assembly of any of clauses 1 through 13, wherein the upper housing includes at least one radiator opening.

Clause 15: The waveguide antenna assembly of clause 14, further comprising a dielectric material disposed within the at least one radiator opening.